[ADD] email_template: added support for 'email' server action.
Email server action are now entirely based on templates.
Added tests.
[IMP] Addons: cleaned server action definition according to refactoring.
[MERGE] Sync with trunk
[MERGE] Sync with trunk
[MERGE] Sync with trunk
[MERGE] Sync with trunk
[DOC] email_template: added changelod
[FIX] crm: fixed a typo in onchange method name
[FIX] email_template: ir_actions: fixed email server action form view, a copy and paste introduced an error
[REM] crm: removed new_email_send, now unused and deprecated with chatter / templates.
[IMP] email_template: server action: better management of template fields, saved but not editable
[IMP] crm: reminder to user: uses a different and more adequate template
[IMP] crm: improved reminder ot user template
[MERGE] Server action cleaning and usability improvements. This branch comes with a server-side branch.

[IMP] Addons: cleaned server action definition according to refactoring.

[ADD] email_template: added support for 'email' server action.
Email server action are now entirely based on templates.

[IMP] crm: fixed an issue with an on_change + specific template used in the email server action to remind users of their forgotten leads

[TEST] email_template: added tests for the email server action